How can I have my occassional backpains and apparently related headaches correctly diagnosed?

Usually with an exam. Back pain and headache can definitely be related. Usually we evaluate back pain with an exam/ x-ray, and based on our clinical findings (or lack of red flag signs of neurological involvement) we will prescribe treatment with medications, home exercise and/or pt. If conservative therapy fails i will usually order more advanced treatment and imaging (MRI) to see if a more complex problem exists.